Hey, this is a really cool project and I have got it completed. Two items that are vexing me. 1. The motor runs all the time, but stops for 650 when the knock is applied correctly (polarity maybe?) I know it is a simple fix, but it is just escaping me. 2. The NPN transistor gets smoking hot. I have the correct resistor and even changed it out with a new one. Still getting hot (very). Thoughts. I love this and we are adding it into our business. Thanks for the help. I will send you a pic of the final project if you would like. It is eventually going to run a 12V relay to a maglock.